In an effort to reduce patient trauma, shorten healing time, and reduce the risk of infection, many surgical procedures that previously required large incisions are now being performed using catheters and minimally invasive techniques. One area in which this is particularly true is in the field of vascular surgery. Medical devices such as ablation balloons or stents are often delivered to a desired location in a patient's body through a catheter that is inserted through a relatively small hole made in the patient's leg, neck or arm. The catheter is advanced through the vasculature to its intended destination and the medical device is then deployed from the catheter.
Some medical devices such as vascular stents are prepackaged in a delivery catheter for use by a physician. However, such pre-loaded catheters are not always easy to route to their intended destination. If a pre-loaded catheter is to, be routed over a guidewire, there must be room for the guidewire to move past the medical device in a lumen of the catheter. Alternatively, a separate guidewire lumen must be provided. In either case the size of the catheter required is increased. In some cases, the pre-loaded catheter is advanced through a lumen of a guide catheter that has been previously placed at the intended destination. This approach requires that the guide catheter be made sufficiently large to accommodate the delivery catheter. However, to reduce patient complications, it is generally desirable to reduce the size of the catheters that are inserted into the patient.
Another problem that can occur during a minimally invasive surgical procedure is that the medical device becomes damaged prior to implantation. After the physician has placed a catheter in the desired location, the physician must insert the medical device into the end of the catheter that remains outside the patient. If the device is small and delicate, the physician may damage it while trying to fit it into the catheter and advance it to the desired location in the patient's body.
Finally, physicians generally want to be free to use the technique for placing a catheter that is best suited to the particular patient and the procedure to be performed. Physicians may not want to use the catheter in which a pre-loaded medical device is sold. For example, the physician may want to use a guide wire, dilator or steering catheter to direct the guide catheter tip into position to then guide the medical device into position.
Given these problems, there is a need for a mechanism that allows a medical device to be delivered to a desired location within a patient's body in a way that does not dictate a physician's choice of particular routing technique or require an increased catheter size and that reduces the risk of damage to the device.